How salt-affected soils can be reclaimed?
The reclamation of salt-affected soils follows the exact reverse of the process by which they are formed. In the case of sodic soils, amendments that will supply a fresh source of soluble calcium to replace the sodium adsorbed by the soil are added. and leaching is carried out until the replaced sodium is removed.
How do you reverse salt in soil?
Gypsum (calcium sulfate) or lime can be used to help leach salt from the soil. The calcium in these products replaces the sodium salt from the soil exchange sites and helps bring the salt into solution. Large concentrations of salt may be leached from a soil in this way.
What are common methods for reclamation of saline soil?
Methods Of Reclamation Or Management Of Saline Soils
- Scraping: The salts accumulated on the surface can be removed by mechanical means.
- Flushing: Washing of surface salts by flushing water.
- Leaching: leaching with good quality water, irrigation or rain is the only practical way to remove excess salts from the soil.
What are the major problems related with salt-affected soils?
Excess salts in soil solution affect the osmotic potential of soil water. The increase in soil water potential (i.e., more negative) makes water harder to extract and less available to plant roots, which can lead to water stress in plants. 3. The uptake of excess chloride can lead to direct damage to plant leaves.
Where are you most likely to find salt-affected soils?
Salt-affected soils occur in all continents and under almost all climatic conditions. Their distribution, however, is relatively more extensive in the arid and semi-arid regions compared to the humid regions.
What is soil reclamation?
Reclamation of sodic soils involves replacement of exchangeable Na by Ca. The source of Ca for replacing adsorbed Na can be external sources such as gypsum, calcium chloride, and irrigation water containing Ca ions, or the soil itself, involving the dissolution of Ca-containing minerals.
What causes high salt in soil?
Soils naturally high in soluble salts are usually found in arid or semi-arid regions, where salts often accumulate because there is not enough rainfall to dissolve them and leach them out of the root zone. Salt spray near coastlines can also cause salts to build up in the soil.
What happens if there is too much salt in soil?
The problem with excess salt in soil is the effects of sodium on plants. Too much salt can cause toxicity but more importantly, it reacts on plant tissues just as it does on ours. It produces an effect called osmotion, which causes important water in plant tissues to be diverted.
How salts accumulate in non irrigated soils?
Salts may accumulate in surface soils by evaporation of saline surface water from poorly drained areas, or by seepage and capillary flow from unconfined or leaky confined aquifers. For some part of the year, water at atmospheric pressure is usually found within a few metres of the surface of a saline seep.
How does soil salinity affect crop production?
Salinity becomes a problem when enough salts accumulate in the root zone to negatively affect plant growth. Excess salts in the root zone hinder plant roots from withdrawing water from surrounding soil. This lowers the amount of water available to the plant, regardless of the amount of water actually in the root zone.
What are the main effects of salt affected soil on plant growth?
Salinity affects production in crops, pastures and trees by interfering with nitrogen uptake, reducing growth and stopping plant reproduction. Some ions (particularly chloride) are toxic to plants and as the concentration of these ions increases, the plant is poisoned and dies.
Where are you most likely to find salt affected soils?
What is salt-affected soil reclamation?
Some salt-affected soils have physical problems that slow water infiltration and increase surface runoff. The reclamation of salt-affected soils can lead to better water management, water use efficiency, and crop production. The first step in reclaiming a salt-affected soil is diagnosis of the problem.
How does irrigation affect the salinity of soil?
Since all irrigation waters carry at least some salt, irrigation may hasten the process of salt accumulation in soils, and reclamation of arid lands by irrigation may be followed by a need for reclamation of salty lands by drainage and leaching.
How does seepage increase the salt content of soil?
Such seepage increases the salt content of the soil. The salt in soils dissolves in the soil water and damages plant growth by preventing the plants from getting needed water from the soil, since the energy required to remove a given quantity of water from a salt solution increases as the salt concentration of the solution increases.
What happens if you put salt in soil?
In some cases, the dissolved salts may be toxic to plants when taken up by the roots. In addition to their detrimental effects on plants, sodium ions from the dissolved salt may become adsorbed by the clay particles of the soil and render the soil very sticky when wet and hard and cloddy when dry.